Triggering New Sensors For Virus Infection

Research reported in the September issue of Nature Immunology identifying a new response factor triggered by intracellular sensors of many types of viruses may open up new ways of enhancing our ability to fight infections.

Viral infections cause immune cells to fight back by making proteins called interferons, which are critical for effective activation of the body's defense mechanisms. This new research gives scientists a novel direction for finding effective treatments for certain types of virus infection.

Many of the signals essential to interferon production have been characterized, and they emanate from myriad different participants. The abundance of such information might indicate that every important way of triggering interferon is known. Recent work has identified new sensors in cells that respond to viral production of double-stranded RNA molecules, but just how these new sensors caused interferon to be produced was unknown.

Shizuo Akira and colleagues have found that a protein they call interferon-beta promoter stimulator 1 (IPS-1) is essential for signaling by the new sensors for production of interferon. Cells that were deficient in IPS-1 made less interferon and were more susceptible to virus infection than normal cells. IPS-1 was identified by a 'brute force' method in which hundreds of candidate proteins were screened for the ability to trigger interferon production. The finding is of importance, as it represents one more potential weapon against the harsh assault viruses can make on our health.